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Biomedical subjects

A Turkes

Publications and source records attributed to A Turkes.

45 records · Page 3Linked to original sources
PubMed1983

Therapeutic potential of the LHRH agonist, ICI 118630, in the treatment of advanced prostatic carcinoma.

8 patients with advanced prostatic carcinoma were treated with the luteinising-hormone releasing-hormone agonist, ICI 118630, for up to 3 months. Patients received subcutaneous injections of ICI 118630 (either 100 micrograms or 250 micrograms daily). At the higher dose level, plasma testosterone concentrations were significantly reduced by day 14 and approximated to those previously recorded in castrated or diethylstilboestrol-treated patients. Plasma concentrations of luteinising hormone and follicle-stimulating hormone were similarly reduced. Reduction in the dose, to 100 micrograms/day, similarly reduced plasma testosterone. ICI 118630 shows considerable potential for the management of patients with advanced carcinoma of the prostate.

Acid Phosphatase↗
PubMed1983

The effect of tamoxifen on plasma growth hormone and prolactin in postmenopausal women with advanced breast cancer.

The effect of tamoxifen on serum levels of basal prolactin and basal and stimulated growth hormone was assessed in 10 women with advanced breast cancer prior to and after 1 and 8 weeks of treatment. Tamoxifen had no effect on basal levels of either hormone or on insulin-stimulated growth hormone. Two of 4 patients undergoing arginine provocation testing had a partial response to tamoxifen and both exhibited marked diminution of growth hormone stimulation which was not seen in the non-responders.

Aged↗
PubMed1982

A simple high-throughput enzymeimmunoassay for norethisterone (norethindrone).

A direct enzymeimmunoassay having the sensitivity required for determining norethisterone concentrations in small aliquots of plasma (10 microliter) has been developed. This assay featured a solid phase antiserum raised against a norethisterone-11 alpha-hemisuccinyl/bovine serum albumin conjugate. The antiserum was coupled to cyanogen bromide-activated magnetisable cellulose, and antibody-bound and free fractions were separated by a simple magnetic device. A norethisterone/horseradish peroxidase conjugate was used as the label; o-phenylenediamine/hydrogen peroxide being the substrate for colour development. The results obtained by this direct EIA, which allowed processing of at least 100 samples per day, were compared with those of a well-validated enzymeimmunoassay featuring solvent extraction and centrifugal separation of antibody-bound and free steroid; the results were in excellent agreement (n = 30; r greater than 0.99) suggesting the usefulness of the simple high-throughput procedure for processing the large sample numbers generated by field investigations and pharmacokinetic studies.

Centrifugation↗
PubMed1981

A radioimmunoassay for ethinyl oestradiol in plasma incorporating an immunosorbent, pre-assay purification procedure.

A radioimmunoassay for plasma ethinyl oestradiol, featuring an immunosorbent extraction procedure, is described. Ethinyl oestradiol (EE2) was extracted using a non-specific, anti-oestrogen serum, raised to an oestradiol-17-hemisuccinate conjugate. The antiserum, coupled to microcrystalline cellulose, selectively extracted EE2 but not norethisterone ( NE), thus conferring specificity on a radioimmunoassay which has previously exhibited unacceptably high cross-reactivity with the synthetic progestagen, norethisterone, often used concomitantly with ethinyl oestradiol. This radioimmunoassay was shown to fulfil accepted assay validation criteria. Levels in subjects not receiving EE2 were less than 25 pmol/l. Circulating concentrations of EE2 could therefore be accurately determined in patients receiving low-dose combined preparations (EE2 35 micrograms; NE 500 micrograms).

Antigen-Antibody Complex↗
PubMed1981

Enzyme immunoassay for specific determination of the synthetic estrogen, ethynyl estradiol, in plasma.

In this enzyme immunoassay for ethynyl estradiol, a conjugate of the 3-(O-carboxymethyl)ether with horseradish peroxidase is used as the label and a conjugate of the 6-(O-carboxymethyl)oxime with bovine serum albumin as the immunogen. A solid-phase antibody procedure is used in separating antibody-bound and free steroid. The lower limit of sensitivity of the assay is 2 pg per assay tube. Interference by synthetic progestagens was minimized by extracting the sample with an anti-estrogen serum before assay. Results obtained with a comparison radioimmunoassay and this procedure agreed well (r greater than 0.98).

Contraceptives, Oral↗
PubMed1980

A sensitive enzymeimmunoassay with a fluorimetric end-point for the determination of testosterone in female plasma and saliva.

A fluorimetric enzymeimmunoassay has been developed having the sensitivity (500 fg/assay tube) required for determining testosterone concentrations in female plasma and saliva samples. The assay featured a solid-phase antiserum raised against an 11 alpha-hydroxytestosterone-11-hemisuccinate bovine serum albumin conjugate, an 11 alpha-hydroxytestosterone-11-hemisuccinate horseradish peroxidase conjugate as the "enzyme label", and p-hydroxyphenylacetic acid as the substrate for the development of fluorescence. Specificity was ensured by "extracting" testosterone from samples with a solid-phase anti testosterone-3-/0-carboxymethyl/-oxime serum. The assay was shown to satisfy accepted validation criteria providing results in good agreement with routine radioimmunoassay procedures in both plasma (r greater than 0.98, n=28) and saliva (r greater than 0.99, n=28). In saliva samples collected at 2 hourly intervals by normal healthy women (n=5) testosterone concentrations showed a well defined circadian rhythm: the mean testosterone concentration in early morning samples (174 pmol/litre) fell by 83% in late evening collections. In healthy female volunteers (n=7), mean daily throughout one complete cycle ranged from 50 to 218 pmol/litre. Following dexamethasone administration testosterone concentrations in plasma fell by approximately 50%, and salivary concentrations were undetectable after one hour. This enzymeimmunoassay may be useful in studies of female infertility.

Adult↗
PubMed1980

A sensitive solid phase enzymeimmunoassay for norethisterone (norethindrone) in saliva and plasma.

A sensitive, solid phase enzymeimmunoassay suitable for determining norethisterone in small aliquots of plasma (10 microliters) and saliva (100 microliters) has been developed. A solid phase antiserum raised against a norethisterone-11 alpha-hemisuccinyl/bovine serum albumin conjugate was prepared by coupling to cyanogen bromide activated cellulose. A norethisterone/horseradish peroxidase conjugate was used as enzyme label, o-phenylenediamine/hydrogen peroxide being the substrate for colour development. The assay had a lower limit of sensitivity of 3 pg/assay tube and satisfied accepted validation criteria. Norethisterone concentrations determined by enzymeimmunoassay and by a well established radioimmunoassay were in excellent agreement in both plasma (r = 0.993, n = 20) and saliva (r = 0.989, n = 15). Plasma and salivary norethisterone concentrations determined in healthy volunteers reached peak values at about 1 hour after administering a norethisterone-containing oral contraceptive preparation. The maximum values achieved in saliva (775--1430 pmol/l) were only approximately 3% of those observed in plama. Since salivary norethisterone concentrations reflected those in plasma, they may be useful in fertility control programmes and pharmacokinetic studies.

Administration, Oral↗
PubMed1979

A sensitive solid phase enzymeimmunoassay for testosterone in plasma and saliva.

A sensitive, solid phase enzymeimmunoassay suitable for determining testosterone concentrations in samll aliquots of plasma (20 microliter) and saliva (200 microliter) has been developed. A solid phase antiserum raised against a testosterone-11 alpha-hemisuccinate/bovine serum albumin conjugate was prepared by coupling to cyanogen bromide activated cellulose. The "enzyme label" was a covalently linked testosterone/horseradish peroxidase conjugate. The assay had a lower limit of sensitivity of 4pg/assay tube and satisfied accepted criteria of specificity and precision. Testosterone concentrations determined by enzyme-immunoassay were in excellent agreement not only with a gas liquid chromatography/mass spectrometry procedure (r=0.96, n=12) but also with the radioimmunoassay in routine use (r=0.95, n=12). The EIA can therefore replace RIA in both the small clinical laboratory and high throughput service centres for determining plasma and salivary testosterone concentrations. In normal males salivary testosterone concentrations reflected circulating steroid levels and indicated the possibility of assaying saliva rather than plasma in clinical studies.

Antibody Specificity↗